Adding upstream version 4.19.249.upstream/4.19.249upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 910 insertions, 0 deletions

diff --git a/fs/ecryptfs/main.c b/fs/ecryptfs/main.c
new file mode 100644
index 000000000..b86a9b3a3
--- /dev/null
+++ b/fs/ecryptfs/main.c
@@ -0,0 +1,910 @@
+/**
+ * eCryptfs: Linux filesystem encryption layer
+ *
+ * Copyright (C) 1997-2003 Erez Zadok
+ * Copyright (C) 2001-2003 Stony Brook University
+ * Copyright (C) 2004-2007 International Business Machines Corp.
+ *   Author(s): Michael A. Halcrow <mahalcro@us.ibm.com>
+ *              Michael C. Thompson <mcthomps@us.ibm.com>
+ *              Tyler Hicks <tyhicks@ou.edu>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of the
+ * License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
+ * 02111-1307, USA.
+ */
+
+#include <linux/dcache.h>
+#include <linux/file.h>
+#include <linux/module.h>
+#include <linux/namei.h>
+#include <linux/skbuff.h>
+#include <linux/mount.h>
+#include <linux/pagemap.h>
+#include <linux/key.h>
+#include <linux/parser.h>
+#include <linux/fs_stack.h>
+#include <linux/slab.h>
+#include <linux/magic.h>
+#include "ecryptfs_kernel.h"
+
+/**
+ * Module parameter that defines the ecryptfs_verbosity level.
+ */
+int ecryptfs_verbosity = 0;
+
+module_param(ecryptfs_verbosity, int, 0);
+MODULE_PARM_DESC(ecryptfs_verbosity,
+		 "Initial verbosity level (0 or 1; defaults to "
+		 "0, which is Quiet)");
+
+/**
+ * Module parameter that defines the number of message buffer elements
+ */
+unsigned int ecryptfs_message_buf_len = ECRYPTFS_DEFAULT_MSG_CTX_ELEMS;
+
+module_param(ecryptfs_message_buf_len, uint, 0);
+MODULE_PARM_DESC(ecryptfs_message_buf_len,
+		 "Number of message buffer elements");
+
+/**
+ * Module parameter that defines the maximum guaranteed amount of time to wait
+ * for a response from ecryptfsd.  The actual sleep time will be, more than
+ * likely, a small amount greater than this specified value, but only less if
+ * the message successfully arrives.
+ */
+signed long ecryptfs_message_wait_timeout = ECRYPTFS_MAX_MSG_CTX_TTL / HZ;
+
+module_param(ecryptfs_message_wait_timeout, long, 0);
+MODULE_PARM_DESC(ecryptfs_message_wait_timeout,
+		 "Maximum number of seconds that an operation will "
+		 "sleep while waiting for a message response from "
+		 "userspace");
+
+/**
+ * Module parameter that is an estimate of the maximum number of users
+ * that will be concurrently using eCryptfs. Set this to the right
+ * value to balance performance and memory use.
+ */
+unsigned int ecryptfs_number_of_users = ECRYPTFS_DEFAULT_NUM_USERS;
+
+module_param(ecryptfs_number_of_users, uint, 0);
+MODULE_PARM_DESC(ecryptfs_number_of_users, "An estimate of the number of "
+		 "concurrent users of eCryptfs");
+
+void __ecryptfs_printk(const char *fmt, ...)
+{
+	va_list args;
+	va_start(args, fmt);
+	if (fmt[1] == '7') { /* KERN_DEBUG */
+		if (ecryptfs_verbosity >= 1)
+			vprintk(fmt, args);
+	} else
+		vprintk(fmt, args);
+	va_end(args);
+}
+
+/**
+ * ecryptfs_init_lower_file
+ * @ecryptfs_dentry: Fully initialized eCryptfs dentry object, with
+ *                   the lower dentry and the lower mount set
+ *
+ * eCryptfs only ever keeps a single open file for every lower
+ * inode. All I/O operations to the lower inode occur through that
+ * file. When the first eCryptfs dentry that interposes with the first
+ * lower dentry for that inode is created, this function creates the
+ * lower file struct and associates it with the eCryptfs
+ * inode. When all eCryptfs files associated with the inode are released, the
+ * file is closed.
+ *
+ * The lower file will be opened with read/write permissions, if
+ * possible. Otherwise, it is opened read-only.
+ *
+ * This function does nothing if a lower file is already
+ * associated with the eCryptfs inode.
+ *
+ * Returns zero on success; non-zero otherwise
+ */
+static int ecryptfs_init_lower_file(struct dentry *dentry,
+				    struct file **lower_file)
+{
+	const struct cred *cred = current_cred();
+	struct path *path = ecryptfs_dentry_to_lower_path(dentry);
+	int rc;
+
+	rc = ecryptfs_privileged_open(lower_file, path->dentry, path->mnt,
+				      cred);
+	if (rc) {
+		printk(KERN_ERR "Error opening lower file "
+		       "for lower_dentry [0x%p] and lower_mnt [0x%p]; "
+		       "rc = [%d]\n", path->dentry, path->mnt, rc);
+		(*lower_file) = NULL;
+	}
+	return rc;
+}
+
+int ecryptfs_get_lower_file(struct dentry *dentry, struct inode *inode)
+{
+	struct ecryptfs_inode_info *inode_info;
+	int count, rc = 0;
+
+	inode_info = ecryptfs_inode_to_private(inode);
+	mutex_lock(&inode_info->lower_file_mutex);
+	count = atomic_inc_return(&inode_info->lower_file_count);
+	if (WARN_ON_ONCE(count < 1))
+		rc = -EINVAL;
+	else if (count == 1) {
+		rc = ecryptfs_init_lower_file(dentry,
+					      &inode_info->lower_file);
+		if (rc)
+			atomic_set(&inode_info->lower_file_count, 0);
+	}
+	mutex_unlock(&inode_info->lower_file_mutex);
+	return rc;
+}
+
+void ecryptfs_put_lower_file(struct inode *inode)
+{
+	struct ecryptfs_inode_info *inode_info;
+
+	inode_info = ecryptfs_inode_to_private(inode);
+	if (atomic_dec_and_mutex_lock(&inode_info->lower_file_count,
+				      &inode_info->lower_file_mutex)) {
+		filemap_write_and_wait(inode->i_mapping);
+		fput(inode_info->lower_file);
+		inode_info->lower_file = NULL;
+		mutex_unlock(&inode_info->lower_file_mutex);
+	}
+}
+
+enum { ecryptfs_opt_sig, ecryptfs_opt_ecryptfs_sig,
+       ecryptfs_opt_cipher, ecryptfs_opt_ecryptfs_cipher,
+       ecryptfs_opt_ecryptfs_key_bytes,
+       ecryptfs_opt_passthrough, ecryptfs_opt_xattr_metadata,
+       ecryptfs_opt_encrypted_view, ecryptfs_opt_fnek_sig,
+       ecryptfs_opt_fn_cipher, ecryptfs_opt_fn_cipher_key_bytes,
+       ecryptfs_opt_unlink_sigs, ecryptfs_opt_mount_auth_tok_only,
+       ecryptfs_opt_check_dev_ruid,
+       ecryptfs_opt_err };
+
+static const match_table_t tokens = {
+	{ecryptfs_opt_sig, "sig=%s"},
+	{ecryptfs_opt_ecryptfs_sig, "ecryptfs_sig=%s"},
+	{ecryptfs_opt_cipher, "cipher=%s"},
+	{ecryptfs_opt_ecryptfs_cipher, "ecryptfs_cipher=%s"},
+	{ecryptfs_opt_ecryptfs_key_bytes, "ecryptfs_key_bytes=%u"},
+	{ecryptfs_opt_passthrough, "ecryptfs_passthrough"},
+	{ecryptfs_opt_xattr_metadata, "ecryptfs_xattr_metadata"},
+	{ecryptfs_opt_encrypted_view, "ecryptfs_encrypted_view"},
+	{ecryptfs_opt_fnek_sig, "ecryptfs_fnek_sig=%s"},
+	{ecryptfs_opt_fn_cipher, "ecryptfs_fn_cipher=%s"},
+	{ecryptfs_opt_fn_cipher_key_bytes, "ecryptfs_fn_key_bytes=%u"},
+	{ecryptfs_opt_unlink_sigs, "ecryptfs_unlink_sigs"},
+	{ecryptfs_opt_mount_auth_tok_only, "ecryptfs_mount_auth_tok_only"},
+	{ecryptfs_opt_check_dev_ruid, "ecryptfs_check_dev_ruid"},
+	{ecryptfs_opt_err, NULL}
+};
+
+static int ecryptfs_init_global_auth_toks(
+	struct ecryptfs_mount_crypt_stat *mount_crypt_stat)
+{
+	struct ecryptfs_global_auth_tok *global_auth_tok;
+	struct ecryptfs_auth_tok *auth_tok;
+	int rc = 0;
+
+	list_for_each_entry(global_auth_tok,
+			    &mount_crypt_stat->global_auth_tok_list,
+			    mount_crypt_stat_list) {
+		rc = ecryptfs_keyring_auth_tok_for_sig(
+			&global_auth_tok->global_auth_tok_key, &auth_tok,
+			global_auth_tok->sig);
+		if (rc) {
+			printk(KERN_ERR "Could not find valid key in user "
+			       "session keyring for sig specified in mount "
+			       "option: [%s]\n", global_auth_tok->sig);
+			global_auth_tok->flags |= ECRYPTFS_AUTH_TOK_INVALID;
+			goto out;
+		} else {
+			global_auth_tok->flags &= ~ECRYPTFS_AUTH_TOK_INVALID;
+			up_write(&(global_auth_tok->global_auth_tok_key)->sem);
+		}
+	}
+out:
+	return rc;
+}
+
+static void ecryptfs_init_mount_crypt_stat(
+	struct ecryptfs_mount_crypt_stat *mount_crypt_stat)
+{
+	memset((void *)mount_crypt_stat, 0,
+	       sizeof(struct ecryptfs_mount_crypt_stat));
+	INIT_LIST_HEAD(&mount_crypt_stat->global_auth_tok_list);
+	mutex_init(&mount_crypt_stat->global_auth_tok_list_mutex);
+	mount_crypt_stat->flags |= ECRYPTFS_MOUNT_CRYPT_STAT_INITIALIZED;
+}
+
+/**
+ * ecryptfs_parse_options
+ * @sb: The ecryptfs super block
+ * @options: The options passed to the kernel
+ * @check_ruid: set to 1 if device uid should be checked against the ruid
+ *
+ * Parse mount options:
+ * debug=N 	   - ecryptfs_verbosity level for debug output
+ * sig=XXX	   - description(signature) of the key to use
+ *
+ * Returns the dentry object of the lower-level (lower/interposed)
+ * directory; We want to mount our stackable file system on top of
+ * that lower directory.
+ *
+ * The signature of the key to use must be the description of a key
+ * already in the keyring. Mounting will fail if the key can not be
+ * found.
+ *
+ * Returns zero on success; non-zero on error
+ */
+static int ecryptfs_parse_options(struct ecryptfs_sb_info *sbi, char *options,
+				  uid_t *check_ruid)
+{
+	char *p;
+	int rc = 0;
+	int sig_set = 0;
+	int cipher_name_set = 0;
+	int fn_cipher_name_set = 0;
+	int cipher_key_bytes;
+	int cipher_key_bytes_set = 0;
+	int fn_cipher_key_bytes;
+	int fn_cipher_key_bytes_set = 0;
+	struct ecryptfs_mount_crypt_stat *mount_crypt_stat =
+		&sbi->mount_crypt_stat;
+	substring_t args[MAX_OPT_ARGS];
+	int token;
+	char *sig_src;
+	char *cipher_name_dst;
+	char *cipher_name_src;
+	char *fn_cipher_name_dst;
+	char *fn_cipher_name_src;
+	char *fnek_dst;
+	char *fnek_src;
+	char *cipher_key_bytes_src;
+	char *fn_cipher_key_bytes_src;
+	u8 cipher_code;
+
+	*check_ruid = 0;
+
+	if (!options) {
+		rc = -EINVAL;
+		goto out;
+	}
+	ecryptfs_init_mount_crypt_stat(mount_crypt_stat);
+	while ((p = strsep(&options, ",")) != NULL) {
+		if (!*p)
+			continue;
+		token = match_token(p, tokens, args);
+		switch (token) {
+		case ecryptfs_opt_sig:
+		case ecryptfs_opt_ecryptfs_sig:
+			sig_src = args[0].from;
+			rc = ecryptfs_add_global_auth_tok(mount_crypt_stat,
+							  sig_src, 0);
+			if (rc) {
+				printk(KERN_ERR "Error attempting to register "
+				       "global sig; rc = [%d]\n", rc);
+				goto out;
+			}
+			sig_set = 1;
+			break;
+		case ecryptfs_opt_cipher:
+		case ecryptfs_opt_ecryptfs_cipher:
+			cipher_name_src = args[0].from;
+			cipher_name_dst =
+				mount_crypt_stat->
+				global_default_cipher_name;
+			strncpy(cipher_name_dst, cipher_name_src,
+				ECRYPTFS_MAX_CIPHER_NAME_SIZE);
+			cipher_name_dst[ECRYPTFS_MAX_CIPHER_NAME_SIZE] = '\0';
+			cipher_name_set = 1;
+			break;
+		case ecryptfs_opt_ecryptfs_key_bytes:
+			cipher_key_bytes_src = args[0].from;
+			cipher_key_bytes =
+				(int)simple_strtol(cipher_key_bytes_src,
+						   &cipher_key_bytes_src, 0);
+			mount_crypt_stat->global_default_cipher_key_size =
+				cipher_key_bytes;
+			cipher_key_bytes_set = 1;
+			break;
+		case ecryptfs_opt_passthrough:
+			mount_crypt_stat->flags |=
+				ECRYPTFS_PLAINTEXT_PASSTHROUGH_ENABLED;
+			break;
+		case ecryptfs_opt_xattr_metadata:
+			mount_crypt_stat->flags |=
+				ECRYPTFS_XATTR_METADATA_ENABLED;
+			break;
+		case ecryptfs_opt_encrypted_view:
+			mount_crypt_stat->flags |=
+				ECRYPTFS_XATTR_METADATA_ENABLED;
+			mount_crypt_stat->flags |=
+				ECRYPTFS_ENCRYPTED_VIEW_ENABLED;
+			break;
+		case ecryptfs_opt_fnek_sig:
+			fnek_src = args[0].from;
+			fnek_dst =
+				mount_crypt_stat->global_default_fnek_sig;
+			strncpy(fnek_dst, fnek_src, ECRYPTFS_SIG_SIZE_HEX);
+			mount_crypt_stat->global_default_fnek_sig[
+				ECRYPTFS_SIG_SIZE_HEX] = '\0';
+			rc = ecryptfs_add_global_auth_tok(
+				mount_crypt_stat,
+				mount_crypt_stat->global_default_fnek_sig,
+				ECRYPTFS_AUTH_TOK_FNEK);
+			if (rc) {
+				printk(KERN_ERR "Error attempting to register "
+				       "global fnek sig [%s]; rc = [%d]\n",
+				       mount_crypt_stat->global_default_fnek_sig,
+				       rc);
+				goto out;
+			}
+			mount_crypt_stat->flags |=
+				(ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES
+				 | ECRYPTFS_GLOBAL_ENCFN_USE_MOUNT_FNEK);
+			break;
+		case ecryptfs_opt_fn_cipher:
+			fn_cipher_name_src = args[0].from;
+			fn_cipher_name_dst =
+				mount_crypt_stat->global_default_fn_cipher_name;
+			strncpy(fn_cipher_name_dst, fn_cipher_name_src,
+				ECRYPTFS_MAX_CIPHER_NAME_SIZE);
+			mount_crypt_stat->global_default_fn_cipher_name[
+				ECRYPTFS_MAX_CIPHER_NAME_SIZE] = '\0';
+			fn_cipher_name_set = 1;
+			break;
+		case ecryptfs_opt_fn_cipher_key_bytes:
+			fn_cipher_key_bytes_src = args[0].from;
+			fn_cipher_key_bytes =
+				(int)simple_strtol(fn_cipher_key_bytes_src,
+						   &fn_cipher_key_bytes_src, 0);
+			mount_crypt_stat->global_default_fn_cipher_key_bytes =
+				fn_cipher_key_bytes;
+			fn_cipher_key_bytes_set = 1;
+			break;
+		case ecryptfs_opt_unlink_sigs:
+			mount_crypt_stat->flags |= ECRYPTFS_UNLINK_SIGS;
+			break;
+		case ecryptfs_opt_mount_auth_tok_only:
+			mount_crypt_stat->flags |=
+				ECRYPTFS_GLOBAL_MOUNT_AUTH_TOK_ONLY;
+			break;
+		case ecryptfs_opt_check_dev_ruid:
+			*check_ruid = 1;
+			break;
+		case ecryptfs_opt_err:
+		default:
+			printk(KERN_WARNING
+			       "%s: eCryptfs: unrecognized option [%s]\n",
+			       __func__, p);
+		}
+	}
+	if (!sig_set) {
+		rc = -EINVAL;
+		ecryptfs_printk(KERN_ERR, "You must supply at least one valid "
+				"auth tok signature as a mount "
+				"parameter; see the eCryptfs README\n");
+		goto out;
+	}
+	if (!cipher_name_set) {
+		int cipher_name_len = strlen(ECRYPTFS_DEFAULT_CIPHER);
+
+		BUG_ON(cipher_name_len > ECRYPTFS_MAX_CIPHER_NAME_SIZE);
+		strcpy(mount_crypt_stat->global_default_cipher_name,
+		       ECRYPTFS_DEFAULT_CIPHER);
+	}
+	if ((mount_crypt_stat->flags & ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES)
+	    && !fn_cipher_name_set)
+		strcpy(mount_crypt_stat->global_default_fn_cipher_name,
+		       mount_crypt_stat->global_default_cipher_name);
+	if (!cipher_key_bytes_set)
+		mount_crypt_stat->global_default_cipher_key_size = 0;
+	if ((mount_crypt_stat->flags & ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES)
+	    && !fn_cipher_key_bytes_set)
+		mount_crypt_stat->global_default_fn_cipher_key_bytes =
+			mount_crypt_stat->global_default_cipher_key_size;
+
+	cipher_code = ecryptfs_code_for_cipher_string(
+		mount_crypt_stat->global_default_cipher_name,
+		mount_crypt_stat->global_default_cipher_key_size);
+	if (!cipher_code) {
+		ecryptfs_printk(KERN_ERR,
+				"eCryptfs doesn't support cipher: %s\n",
+				mount_crypt_stat->global_default_cipher_name);
+		rc = -EINVAL;
+		goto out;
+	}
+
+	mutex_lock(&key_tfm_list_mutex);
+	if (!ecryptfs_tfm_exists(mount_crypt_stat->global_default_cipher_name,
+				 NULL)) {
+		rc = ecryptfs_add_new_key_tfm(
+			NULL, mount_crypt_stat->global_default_cipher_name,
+			mount_crypt_stat->global_default_cipher_key_size);
+		if (rc) {
+			printk(KERN_ERR "Error attempting to initialize "
+			       "cipher with name = [%s] and key size = [%td]; "
+			       "rc = [%d]\n",
+			       mount_crypt_stat->global_default_cipher_name,
+			       mount_crypt_stat->global_default_cipher_key_size,
+			       rc);
+			rc = -EINVAL;
+			mutex_unlock(&key_tfm_list_mutex);
+			goto out;
+		}
+	}
+	if ((mount_crypt_stat->flags & ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES)
+	    && !ecryptfs_tfm_exists(
+		    mount_crypt_stat->global_default_fn_cipher_name, NULL)) {
+		rc = ecryptfs_add_new_key_tfm(
+			NULL, mount_crypt_stat->global_default_fn_cipher_name,
+			mount_crypt_stat->global_default_fn_cipher_key_bytes);
+		if (rc) {
+			printk(KERN_ERR "Error attempting to initialize "
+			       "cipher with name = [%s] and key size = [%td]; "
+			       "rc = [%d]\n",
+			       mount_crypt_stat->global_default_fn_cipher_name,
+			       mount_crypt_stat->global_default_fn_cipher_key_bytes,
+			       rc);
+			rc = -EINVAL;
+			mutex_unlock(&key_tfm_list_mutex);
+			goto out;
+		}
+	}
+	mutex_unlock(&key_tfm_list_mutex);
+	rc = ecryptfs_init_global_auth_toks(mount_crypt_stat);
+	if (rc)
+		printk(KERN_WARNING "One or more global auth toks could not "
+		       "properly register; rc = [%d]\n", rc);
+out:
+	return rc;
+}
+
+struct kmem_cache *ecryptfs_sb_info_cache;
+static struct file_system_type ecryptfs_fs_type;
+
+/**
+ * ecryptfs_get_sb
+ * @fs_type
+ * @flags
+ * @dev_name: The path to mount over
+ * @raw_data: The options passed into the kernel
+ */
+static struct dentry *ecryptfs_mount(struct file_system_type *fs_type, int flags,
+			const char *dev_name, void *raw_data)
+{
+	struct super_block *s;
+	struct ecryptfs_sb_info *sbi;
+	struct ecryptfs_mount_crypt_stat *mount_crypt_stat;
+	struct ecryptfs_dentry_info *root_info;
+	const char *err = "Getting sb failed";
+	struct inode *inode;
+	struct path path;
+	uid_t check_ruid;
+	int rc;
+
+	sbi = kmem_cache_zalloc(ecryptfs_sb_info_cache, GFP_KERNEL);
+	if (!sbi) {
+		rc = -ENOMEM;
+		goto out;
+	}
+
+	if (!dev_name) {
+		rc = -EINVAL;
+		err = "Device name cannot be null";
+		goto out;
+	}
+
+	rc = ecryptfs_parse_options(sbi, raw_data, &check_ruid);
+	if (rc) {
+		err = "Error parsing options";
+		goto out;
+	}
+	mount_crypt_stat = &sbi->mount_crypt_stat;
+
+	s = sget(fs_type, NULL, set_anon_super, flags, NULL);
+	if (IS_ERR(s)) {
+		rc = PTR_ERR(s);
+		goto out;
+	}
+
+	rc = super_setup_bdi(s);
+	if (rc)
+		goto out1;
+
+	ecryptfs_set_superblock_private(s, sbi);
+
+	/* ->kill_sb() will take care of sbi after that point */
+	sbi = NULL;
+	s->s_op = &ecryptfs_sops;
+	s->s_xattr = ecryptfs_xattr_handlers;
+	s->s_d_op = &ecryptfs_dops;
+
+	err = "Reading sb failed";
+	rc = kern_path(dev_name, LOOKUP_FOLLOW | LOOKUP_DIRECTORY, &path);
+	if (rc) {
+		ecryptfs_printk(KERN_WARNING, "kern_path() failed\n");
+		goto out1;
+	}
+	if (path.dentry->d_sb->s_type == &ecryptfs_fs_type) {
+		rc = -EINVAL;
+		printk(KERN_ERR "Mount on filesystem of type "
+			"eCryptfs explicitly disallowed due to "
+			"known incompatibilities\n");
+		goto out_free;
+	}
+
+	if (check_ruid && !uid_eq(d_inode(path.dentry)->i_uid, current_uid())) {
+		rc = -EPERM;
+		printk(KERN_ERR "Mount of device (uid: %d) not owned by "
+		       "requested user (uid: %d)\n",
+			i_uid_read(d_inode(path.dentry)),
+			from_kuid(&init_user_ns, current_uid()));
+		goto out_free;
+	}
+
+	ecryptfs_set_superblock_lower(s, path.dentry->d_sb);
+
+	/**
+	 * Set the POSIX ACL flag based on whether they're enabled in the lower
+	 * mount.
+	 */
+	s->s_flags = flags & ~SB_POSIXACL;
+	s->s_flags |= path.dentry->d_sb->s_flags & SB_POSIXACL;
+
+	/**
+	 * Force a read-only eCryptfs mount when:
+	 *   1) The lower mount is ro
+	 *   2) The ecryptfs_encrypted_view mount option is specified
+	 */
+	if (sb_rdonly(path.dentry->d_sb) || mount_crypt_stat->flags & ECRYPTFS_ENCRYPTED_VIEW_ENABLED)
+		s->s_flags |= SB_RDONLY;
+
+	s->s_maxbytes = path.dentry->d_sb->s_maxbytes;
+	s->s_blocksize = path.dentry->d_sb->s_blocksize;
+	s->s_magic = ECRYPTFS_SUPER_MAGIC;
+	s->s_stack_depth = path.dentry->d_sb->s_stack_depth + 1;
+
+	rc = -EINVAL;
+	if (s->s_stack_depth > FILESYSTEM_MAX_STACK_DEPTH) {
+		pr_err("eCryptfs: maximum fs stacking depth exceeded\n");
+		goto out_free;
+	}
+
+	inode = ecryptfs_get_inode(d_inode(path.dentry), s);
+	rc = PTR_ERR(inode);
+	if (IS_ERR(inode))
+		goto out_free;
+
+	s->s_root = d_make_root(inode);
+	if (!s->s_root) {
+		rc = -ENOMEM;
+		goto out_free;
+	}
+
+	rc = -ENOMEM;
+	root_info = kmem_cache_zalloc(ecryptfs_dentry_info_cache, GFP_KERNEL);
+	if (!root_info)
+		goto out_free;
+
+	/* ->kill_sb() will take care of root_info */
+	ecryptfs_set_dentry_private(s->s_root, root_info);
+	root_info->lower_path = path;
+
+	s->s_flags |= SB_ACTIVE;
+	return dget(s->s_root);
+
+out_free:
+	path_put(&path);
+out1:
+	deactivate_locked_super(s);
+out:
+	if (sbi) {
+		ecryptfs_destroy_mount_crypt_stat(&sbi->mount_crypt_stat);
+		kmem_cache_free(ecryptfs_sb_info_cache, sbi);
+	}
+	printk(KERN_ERR "%s; rc = [%d]\n", err, rc);
+	return ERR_PTR(rc);
+}
+
+/**
+ * ecryptfs_kill_block_super
+ * @sb: The ecryptfs super block
+ *
+ * Used to bring the superblock down and free the private data.
+ */
+static void ecryptfs_kill_block_super(struct super_block *sb)
+{
+	struct ecryptfs_sb_info *sb_info = ecryptfs_superblock_to_private(sb);
+	kill_anon_super(sb);
+	if (!sb_info)
+		return;
+	ecryptfs_destroy_mount_crypt_stat(&sb_info->mount_crypt_stat);
+	kmem_cache_free(ecryptfs_sb_info_cache, sb_info);
+}
+
+static struct file_system_type ecryptfs_fs_type = {
+	.owner = THIS_MODULE,
+	.name = "ecryptfs",
+	.mount = ecryptfs_mount,
+	.kill_sb = ecryptfs_kill_block_super,
+	.fs_flags = 0
+};
+MODULE_ALIAS_FS("ecryptfs");
+
+/**
+ * inode_info_init_once
+ *
+ * Initializes the ecryptfs_inode_info_cache when it is created
+ */
+static void
+inode_info_init_once(void *vptr)
+{
+	struct ecryptfs_inode_info *ei = (struct ecryptfs_inode_info *)vptr;
+
+	inode_init_once(&ei->vfs_inode);
+}
+
+static struct ecryptfs_cache_info {
+	struct kmem_cache **cache;
+	const char *name;
+	size_t size;
+	slab_flags_t flags;
+	void (*ctor)(void *obj);
+} ecryptfs_cache_infos[] = {
+	{
+		.cache = &ecryptfs_auth_tok_list_item_cache,
+		.name = "ecryptfs_auth_tok_list_item",
+		.size = sizeof(struct ecryptfs_auth_tok_list_item),
+	},
+	{
+		.cache = &ecryptfs_file_info_cache,
+		.name = "ecryptfs_file_cache",
+		.size = sizeof(struct ecryptfs_file_info),
+	},
+	{
+		.cache = &ecryptfs_dentry_info_cache,
+		.name = "ecryptfs_dentry_info_cache",
+		.size = sizeof(struct ecryptfs_dentry_info),
+	},
+	{
+		.cache = &ecryptfs_inode_info_cache,
+		.name = "ecryptfs_inode_cache",
+		.size = sizeof(struct ecryptfs_inode_info),
+		.flags = SLAB_ACCOUNT,
+		.ctor = inode_info_init_once,
+	},
+	{
+		.cache = &ecryptfs_sb_info_cache,
+		.name = "ecryptfs_sb_cache",
+		.size = sizeof(struct ecryptfs_sb_info),
+	},
+	{
+		.cache = &ecryptfs_header_cache,
+		.name = "ecryptfs_headers",
+		.size = PAGE_SIZE,
+	},
+	{
+		.cache = &ecryptfs_xattr_cache,
+		.name = "ecryptfs_xattr_cache",
+		.size = PAGE_SIZE,
+	},
+	{
+		.cache = &ecryptfs_key_record_cache,
+		.name = "ecryptfs_key_record_cache",
+		.size = sizeof(struct ecryptfs_key_record),
+	},
+	{
+		.cache = &ecryptfs_key_sig_cache,
+		.name = "ecryptfs_key_sig_cache",
+		.size = sizeof(struct ecryptfs_key_sig),
+	},
+	{
+		.cache = &ecryptfs_global_auth_tok_cache,
+		.name = "ecryptfs_global_auth_tok_cache",
+		.size = sizeof(struct ecryptfs_global_auth_tok),
+	},
+	{
+		.cache = &ecryptfs_key_tfm_cache,
+		.name = "ecryptfs_key_tfm_cache",
+		.size = sizeof(struct ecryptfs_key_tfm),
+	},
+};
+
+static void ecryptfs_free_kmem_caches(void)
+{
+	int i;
+
+	/*
+	 * Make sure all delayed rcu free inodes are flushed before we
+	 * destroy cache.
+	 */
+	rcu_barrier();
+
+	for (i = 0; i < ARRAY_SIZE(ecryptfs_cache_infos); i++) {
+		struct ecryptfs_cache_info *info;
+
+		info = &ecryptfs_cache_infos[i];
+		kmem_cache_destroy(*(info->cache));
+	}
+}
+
+/**
+ * ecryptfs_init_kmem_caches
+ *
+ * Returns zero on success; non-zero otherwise
+ */
+static int ecryptfs_init_kmem_caches(void)
+{
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(ecryptfs_cache_infos); i++) {
+		struct ecryptfs_cache_info *info;
+
+		info = &ecryptfs_cache_infos[i];
+		*(info->cache) = kmem_cache_create(info->name, info->size, 0,
+				SLAB_HWCACHE_ALIGN | info->flags, info->ctor);
+		if (!*(info->cache)) {
+			ecryptfs_free_kmem_caches();
+			ecryptfs_printk(KERN_WARNING, "%s: "
+					"kmem_cache_create failed\n",
+					info->name);
+			return -ENOMEM;
+		}
+	}
+	return 0;
+}
+
+static struct kobject *ecryptfs_kobj;
+
+static ssize_t version_show(struct kobject *kobj,
+			    struct kobj_attribute *attr, char *buff)
+{
+	return snprintf(buff, PAGE_SIZE, "%d\n", ECRYPTFS_VERSIONING_MASK);
+}
+
+static struct kobj_attribute version_attr = __ATTR_RO(version);
+
+static struct attribute *attributes[] = {
+	&version_attr.attr,
+	NULL,
+};
+
+static const struct attribute_group attr_group = {
+	.attrs = attributes,
+};
+
+static int do_sysfs_registration(void)
+{
+	int rc;
+
+	ecryptfs_kobj = kobject_create_and_add("ecryptfs", fs_kobj);
+	if (!ecryptfs_kobj) {
+		printk(KERN_ERR "Unable to create ecryptfs kset\n");
+		rc = -ENOMEM;
+		goto out;
+	}
+	rc = sysfs_create_group(ecryptfs_kobj, &attr_group);
+	if (rc) {
+		printk(KERN_ERR
+		       "Unable to create ecryptfs version attributes\n");
+		kobject_put(ecryptfs_kobj);
+	}
+out:
+	return rc;
+}
+
+static void do_sysfs_unregistration(void)
+{
+	sysfs_remove_group(ecryptfs_kobj, &attr_group);
+	kobject_put(ecryptfs_kobj);
+}
+
+static int __init ecryptfs_init(void)
+{
+	int rc;
+
+	if (ECRYPTFS_DEFAULT_EXTENT_SIZE > PAGE_SIZE) {
+		rc = -EINVAL;
+		ecryptfs_printk(KERN_ERR, "The eCryptfs extent size is "
+				"larger than the host's page size, and so "
+				"eCryptfs cannot run on this system. The "
+				"default eCryptfs extent size is [%u] bytes; "
+				"the page size is [%lu] bytes.\n",
+				ECRYPTFS_DEFAULT_EXTENT_SIZE,
+				(unsigned long)PAGE_SIZE);
+		goto out;
+	}
+	rc = ecryptfs_init_kmem_caches();
+	if (rc) {
+		printk(KERN_ERR
+		       "Failed to allocate one or more kmem_cache objects\n");
+		goto out;
+	}
+	rc = do_sysfs_registration();
+	if (rc) {
+		printk(KERN_ERR "sysfs registration failed\n");
+		goto out_free_kmem_caches;
+	}
+	rc = ecryptfs_init_kthread();
+	if (rc) {
+		printk(KERN_ERR "%s: kthread initialization failed; "
+		       "rc = [%d]\n", __func__, rc);
+		goto out_do_sysfs_unregistration;
+	}
+	rc = ecryptfs_init_messaging();
+	if (rc) {
+		printk(KERN_ERR "Failure occurred while attempting to "
+				"initialize the communications channel to "
+				"ecryptfsd\n");
+		goto out_destroy_kthread;
+	}
+	rc = ecryptfs_init_crypto();
+	if (rc) {
+		printk(KERN_ERR "Failure whilst attempting to init crypto; "
+		       "rc = [%d]\n", rc);
+		goto out_release_messaging;
+	}
+	rc = register_filesystem(&ecryptfs_fs_type);
+	if (rc) {
+		printk(KERN_ERR "Failed to register filesystem\n");
+		goto out_destroy_crypto;
+	}
+	if (ecryptfs_verbosity > 0)
+		printk(KERN_CRIT "eCryptfs verbosity set to %d. Secret values "
+			"will be written to the syslog!\n", ecryptfs_verbosity);
+
+	goto out;
+out_destroy_crypto:
+	ecryptfs_destroy_crypto();
+out_release_messaging:
+	ecryptfs_release_messaging();
+out_destroy_kthread:
+	ecryptfs_destroy_kthread();
+out_do_sysfs_unregistration:
+	do_sysfs_unregistration();
+out_free_kmem_caches:
+	ecryptfs_free_kmem_caches();
+out:
+	return rc;
+}
+
+static void __exit ecryptfs_exit(void)
+{
+	int rc;
+
+	rc = ecryptfs_destroy_crypto();
+	if (rc)
+		printk(KERN_ERR "Failure whilst attempting to destroy crypto; "
+		       "rc = [%d]\n", rc);
+	ecryptfs_release_messaging();
+	ecryptfs_destroy_kthread();
+	do_sysfs_unregistration();
+	unregister_filesystem(&ecryptfs_fs_type);
+	ecryptfs_free_kmem_caches();
+}
+
+MODULE_AUTHOR("Michael A. Halcrow <mhalcrow@us.ibm.com>");
+MODULE_DESCRIPTION("eCryptfs");
+
+MODULE_LICENSE("GPL");
+
+module_init(ecryptfs_init)
+module_exit(ecryptfs_exit)